refactor: bump syn to v3

Cargo.toml

@@ -31,7 +31,7 @@ quote = "1"
 heck = "0.5"
 
 [dependencies.syn]
-version = "2.0.85"
+version = "3.0"
 default-features = false
 features = ["clone-impls", "extra-traits", "fold", "full", "parsing", "printing"]
 

src/bindgen/ir/function.rs

@@ -225,16 +225,21 @@ trait SynFnArgHelpers {
 fn gen_self_type(receiver: &syn::Receiver) -> Result<Type, String> {
     let mut self_ty = Type::Path(GenericPath::self_path());
 
-    // Custom self type
-    if receiver.colon_token.is_some() {
-        self_ty = Type::load(receiver.ty.as_ref())?.unwrap_or(self_ty);
-    }
+    let is_const = match &receiver.kind {
+        syn::ReceiverKind::Reference(_, _, mut_token) => mut_token.is_none(),
+        // Custom self type
+        syn::ReceiverKind::Typed(_, ty) => {
+            self_ty = Type::load(ty)?.unwrap_or(self_ty);
 
-    if receiver.reference.is_none() {
-        return Ok(self_ty);
-    }
+            match &**ty {
+                syn::Type::Reference(ref_ty) => ref_ty.mutability.is_none(),
+                _ => return Ok(self_ty),
+            }
+        }
+        syn::ReceiverKind::Value => return Ok(self_ty),
+        _ => return Err(String::from("Receiver is of an unsupported kind")),
+    };
 
-    let is_const = receiver.mutability.is_none();
     Ok(Type::Ptr {
         ty: Box::new(self_ty),
         is_const,

src/bindgen/ir/generic_path.rs

@@ -40,7 +40,7 @@ impl GenericParam {
                 ref default,
                 ..
             }) => {
-                let default = match default.as_ref().map(Type::load).transpose()? {
+                let default = match default.as_ref().map(|(_, ty)| Type::load(ty)).transpose()? {
                     None => None,
                     Some(None) => Some(GenericArgument::Type(Type::Primitive(PrimitiveType::Void))),
                     Some(Some(ty)) => Some(GenericArgument::Type(ty)),
@@ -69,7 +69,7 @@ impl GenericParam {
                     ty: GenericParamType::Const(ty),
                     default: default
                         .as_ref()
-                        .map(ConstExpr::load)
+                        .map(|(_, ty)| ConstExpr::load(ty))
                         .transpose()?
                         .map(GenericArgument::Const),
                 })),

src/bindgen/ir/ty.rs

@@ -375,7 +375,7 @@ impl Type {
                     None => Type::Primitive(PrimitiveType::Void),
                 };
 
-                let is_const = pointer.mutability.is_none();
+                let is_const = matches!(pointer.mutability, syn::PointerMutability::Const(_));
                 Type::Ptr {
                     ty: Box::new(converted),
                     is_const,
@@ -412,7 +412,7 @@ impl Type {
                 let len = ConstExpr::load(len)?;
                 Type::Array(Box::new(converted), len)
             }
-            syn::Type::BareFn(ref function) => {
+            syn::Type::FnPtr(ref function) => {
                 let mut wildcard_counter = 0;
                 let mut args = function.inputs.iter().try_skip_map(|x| {
                     Type::load(&x.ty).map(|opt_ty| {